The Food and Drug Administration is asking doctors to stop prescribing combination medications that contain more than 325 milligrams of acetaminophen per pill, because of long-standing concerns about liver damage.

The move, announced Tuesday, is one of a series of actions the FDA is taking to limit high-dose use of the popular painkiller. FDA already has asked drug-makers to stop producing combination prescription medications with higher doses. More than half of manufacturers have complied, according to the FDA statement.

The products typically combine acetaminophen with opioid painkillers, such as hydrocodone and codeine, and are commonly prescribed after injuries, surgeries and dental procedures.

The agency says it soon will withdraw approval for any of those medications containing more than 325 mg of acetaminophen. It also said that it is planning new regulations on over-the-counter acetaminophen, but did not give details.

Some non-prescription painkillers, such as Extra Strength Tylenol, contain 500 mg of acetaminophen in each pill. Tylenol's maker Johnson & Johnson recently announced it was adding warning labels to bottle caps to remind consumers to read the label for dosing and safety instructions.

In the new statement, FDA said: "There are no available data to show that taking more than 325 mg of acetaminophen per dosage unit provides additional benefit that outweighs the added risks for liver injury. Further, limiting the amount of acetaminophen per dosage unit will reduce the risk of severe liver injury from inadvertent acetaminophen overdose, which can lead to liver failure, liver transplant, and death."

FDA says it's OK for doctors to prescribe two-pill doses, for a total dose of 650 mg, when that's medically appropriate.

Overdoses from acetaminophen send 56,000 people to emergency rooms and kill about 500 each year, according to FDA. The drug is a leading cause of acute liver failure.

FDA has previously said that most cases of liver damage occur in patients who take more than the maximum recommended dose of 4,000 mg in 24 hours.